Field of the Disclosure
The present disclosure relates to an induction heat cooking apparatus, and more particularly, to an induction heat cooking apparatus which includes a plurality of switching devices and a plurality of resonance circuits, and a control method thereof.
Background
Generally, an induction heat cooking apparatus is an electric cooking apparatus performing a cooking function using a method in which a high-frequency current causes to flow through a working coil or a heating coil, and an eddy current flows when a strong line of magnetic force that is accordingly generated passes through a cooking container, and thus the cooking container itself is heated.
In a basic heating principle of the induction heat cooking apparatus, as the current is applied to the heating coil, the cooking container formed of a magnetic material generates heat due to induction heating, the cooking container itself is heated by the generated heat, and a cooking operation is performed.
An inverter used in the induction heat cooking apparatus serves to switch a voltage applied to the heating coil which causes the high-frequency current to flow through the heating coil. The inverter drives a switch device configured with an insulated gate bipolar transistor (IGBT) so that the high-frequency current flows through the heating coil and thus a high-frequency magnetic field is formed at the heating coil.
When two heating coils are provided at the induction heat cooking apparatus, two inverters having four switching devices are required to operate the two heating coils.
FIG. 1 is a view illustrating a conventional induction heat cooking apparatus.
FIG. 1 illustrates an induction heat cooking apparatus including two inverters and two heating coils.
Referring to FIG. 1, the induction heat cooking apparatus includes a rectifier 10, a first inverter 20, a second inverter 30, a first heating coil 40, a second heating coil 50, a first resonant capacitor 60, and a second resonant capacitor 70.
In the first and second inverters 20 and 30, two switching devices which switch input power are connected in series, and the first and second heating coils 40 and 50 driven by output voltages of the switching devices are connected to connection points of the serially connected switching devices, respectively. And the resonant capacitors 60 and 70 are connected to other sides of the first and second heating coils 40 and 50.
The switching devices are driven by a driving part, and controlled at a switching time output from the driving part to be alternately operated, and thus a high-frequency voltage is applied to the heating coil. And since an ON/OFF time of the switching devices applied from the driving part is controlled to be gradually compensated, the voltage supplied to the heating coil is changed from a low voltage to a high voltage.
However, such an induction heat cooking apparatus should include two inverter circuits having four switching devices to operate two heating coils. Therefore, problems arise of a volume of a product increasing, and a price of the product also increasing.
In addition, when the number of heating coils increases to three or more, a plurality of switching devices are required according to the number of heating coils.